Embodiments of the present invention include a disk drive actuator arm for reducing amplitude of vibration modes substantially planar to a disk surface. The actuator arm comprises a plurality of head arms coupled to the actuator arm, the head arms substantially equally spaced and substantially parallel to each other. The actuator arm further includes a damping material bonded to a surface of one of the plurality of head arms, wherein the surface is substantially parallel to the plurality of head arms. The actuator arm further includes a mass bonded to the damping material wherein the mass dampens the amplitude of vibration modes substantially planar to the disk surface.